Structurally enhanced plastics with filler reinforcements

ABSTRACT

A composition comprising a fluid, and a material dispersed in the fluid, the material made up of particles having a complex three dimensional surface area such as a sharp blade-like surface, the particles having an aspect ratio larger than 0.7 for promoting kinetic boundary layer mixing in a non-linear-viscosity zone. The composition may further include an additive dispersed in the fluid. The fluid may be a thermopolymer material. A method of extruding the fluid includes feeding the fluid into an extruder, feeding additives into the extruder, feeding a material into the extruder, passing the material through a mixing zone in the extruder to disperse the material within the fluid wherein the material migrates to a boundary layer of the fluid to promote kinetic mixing of the additives within the fluid, the kinetic mixing taking place in a non-linear viscosity zone.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Division of U.S. patent application Ser. No.14/292,424, titled, “STRUCTURALLY ENHANCED PLASTICS WITH FILLERREINFORCEMENTS”, filed May 30, 2014, which is a Continuation of U.S.patent application Ser. No. 13/757,322, titled, “STRUCTURALLY ENHANCEDPLASTICS WITH FILLER REINFORCEMENTS,” filed Feb. 1, 2013, which is aDivisional of U.S. patent application Ser. No. 12/572,942, titled“STRUCTURALLY ENHANCED POLYMER WITH FILLER REINFORCEMENTS,” filed Oct.2, 2009, which is a Continuation-in-Part of U.S. patent application Ser.No. 12/412,357, titled “STRUCTURALLY ENHANCED PLASTICS WITH FILLERREINFORCEMENTS,” filed Mar. 26, 2009, both of which claim priority toU.S. Provisional Patent Application No. 61/070,876 titled “STRUCTURALLYENHANCED POLYMER WITH FILLER REINFORCEMENTS,” filed Mar. 26, 2008, thecontents of each which are hereby incorporated by reference.

FIELD OF THE INVENTION

A composition for promoting kinetic mixing of additives within anon-linear viscosity zone of a fluid such as a thermoplastic material.

BACKGROUND OF THE INVENTION

An extrusion process is one of the most economic methods ofmanufacturing to produce engineering structural materials. Typically, anextrusion process is used to manufacture lengths of extruded membershaving a uniform cross-section. The cross-section of the members may beof various simple shapes such as circular, annular, or rectangular. Thecross-section of the members may also be very complex, includinginternal support structures and/or having an irregular periphery.

Typically, an extrusion process utilizes thermoplastic polymer compoundsthat are introduced into a feed hopper, Thermoplastic polymer compoundscan be in powder, liquid, cubed, palletized and/or any other extrudableform. The thermoplastic polymer can be virgin, recycled, or a mixture ofboth. An example of a typical extruder is shown in FIG. 1.

The plastic industry has used fillers to lower resin costs duringmanufacturing. Typical fillers include calcium carbonate, talc, woodfiber, and a variety of others. In addition to providing a cost savings,adding fillers to plastics reduces the coefficient of thermal expansion,increases mechanical strength, and in some cases lowers the density.

Calcium carbonate and talc have no structural strength or fiberorientation to improve structural stability. Talc is bonded together byweak Van der Waal's forces, which allow the material to cleave again andagain when pressure is applied to its surface. Even though test resultsindicate that talc imparts a variety of benefits to polymers, forinstance higher stiffness and improved dimensional stability, talc actslike a micro-filler with lubricating properties.

Calcium carbonate has similar properties, but has a water absorptionproblem, which limits its application because of environmentaldegradation. Talc avoids this problem since it is hydrophobic.

Wood fiber adds some dimensional stability because of the fibercharacteristics interaction with the plastic but wood fiber also suffersfrom environmental degradation. All three of these common fillers areeconomically feasible but are structurally limited.

Research efforts have focused on farm waste fibers such as rice hulls,sugar cane fiber, wheat straw and a variety of other fibers to be usedas low-cost fillers inside plastics. The use of wood fiber as a fillerpresents similar difficulties to the above-referenced farm waste fibers.

There are three types of commonly used mixing principles:

1. Static mixing: liquids flowing around fixed objects either by forceproduced flow by pressure through mechanical means or gravity inducedflow.

2. Dynamic mixing: liquid induced mixing by mechanical agitation withtypical impellers, i.e., impellers and wiping blade and sheer designs aswell as dual or single screw agitation designs.

3. Kinetic mixing: liquid is mixed by velocity impacts on a surface orimpacts of two or more liquids impinging on each other.

All three of the above mixing methods have one thing in common thathinders the optimizing of mixing regardless of the fluid being combinedand regardless of whether the materials being mixed are polar, nonpolar,organic or inorganic etc. or if it is a filled material withcompressible or non-compressible fillers.

All incompressible fluids have a wall effect or a boundary layer effectwhere the fluid velocity is greatly reduced at the wall or mechanicalinterface. Static mixing systems use this boundary layer to fold orblend the liquid using this resistive force to promote agitation.

Dynamic mixing, regardless of the geometry of mixing blades or turbine,results in dead zones and incomplete mixing because of the boundarylayer. Dynamic mixing uses high shear and a screw blade designed to usethe boundary layer to promote friction and compression by centrifugalforces to accomplish agitation while maintaining an incomplete mixedboundary layer on mechanical surfaces.

Kinetic mixing suffers from boundary layer effects on velocity profilesboth on the incoming streams and at the injector tip. However, thissystem suffers minimal effects of boundary layer except for transportfluid phenomena.

A further explanation of the boundary layer follows. Aerodynamic forcesdepend in a complex way on the viscosity of the fluid. As the fluidmoves past the object, the molecules right next to the surface stick tothe surface. The molecules just above the surface are slowed down intheir collisions with the molecules sticking to the surface. Thesemolecules in turn slow down the flow just above them. The farther onemoves away from the surface, the fewer the collisions affected by theobject surface. This creates a thin layer of fluid near the surface inwhich the velocity changes from zero at the surface to the free streamvalue away from the surface. Engineers call this layer the boundarylayer because it occurs on the boundary of the fluid.

As an object moves through a fluid, or as a fluid moves past an object,the molecules of the fluid near the object are disturbed and move aroundthe object. Aerodynamic forces are generated between the fluid and theobject. The magnitude of these forces depend on the shape of the object,the speed of the object, the mass of the fluid going by the object andon two other important properties of the fluid; the viscosity, orstickiness, and the compressibility, or springiness, of the fluid. Toproperly model these effects, aerospace engineers use similarityparameters which are ratios of these effects to other forces present inthe problem. If two experiments have the same values for the similarityparameters, then the relative importance of the forces are beingcorrectly modeled.

FIG. 2A shows the streamwise velocity variation from free stream to thesurface. In reality, the effects are three dimensional. From theconservation of mass in three dimensions, a change in velocity in thestreamwise direction causes a change in velocity in the other directionsas well. There is a small component of velocity perpendicular to thesurface which displaces or moves the flow above it. One can define thethickness of the boundary layer to be the amount of this displacement.The displacement thickness depends on the Reynolds number, which is theratio of inertial (resistant to change or motion) forces to viscous(heavy and gluey) forces and is given by the equation: Reynolds number(Re) equals velocity (V) times density (r) times a characteristic length(l) divided by the viscosity coefficient (mu), i.e., Re=V*r*l/mu.

As can be seen in FIG. 2A, boundary layers may be either laminar(layered), or turbulent (disordered) depending on the value of theReynolds number. For lower Reynolds numbers, the boundary layer islaminar and the streamwise velocity changes uniformly as one moves awayfrom the wall, as shown on the left side of FIG. 2A. For higher Reynoldsnumbers, the boundary layer is turbulent and the streamwise velocity ischaracterized by unsteady (changing with time) swirling flows inside theboundary layer. The external flow reacts to the edge of the boundarylayer just as it would to the physical surface of an object. So theboundary layer gives any object an “effective” shape which is usuallyslightly different from the physical shape. The boundary layer may liftoff or “separate” from the body and create an effective shape muchdifferent from the physical shape. This happens because the flow in theboundary has very low energy (relative to the free stream) and is moreeasily driven by changes in pressure. Flow separation is the reason forairplane wing stall at high angle of attack. The effects of the boundarylayer on lift are contained in the lift coefficient and the effects ondrag are contained in the drag coefficient.

Boundary-Layer Flow

That portion of a fluid flow, near a solid surface, is where shearstresses are significant and inviscid-flow assumption may not be used.All solid surfaces interact with a viscous fluid flow because of theno-slip condition, a physical requirement that the fluid and solid haveequal velocities at their interface. Thus, a fluid flow is retarded by afixed solid surface, and a finite, slow-moving boundary layer is formed.A requirement for the boundary layer to be thin is that the Reynoldsnumber of the body be large, 10³ or more. Under these conditions theflow outside the boundary layer is essentially inviscid and plays therole of a driving mechanism for the layer.

Referring now to FIG. 2B, a typical low-speed or laminar boundary layeris shown in the illustration. Such a display of the streamwise flowvector variation near the wall is called a velocity profile. The no-slipcondition requires that u(x,0)=0, as shown, where u is the velocity offlow in the boundary layer. The velocity rises monotonically withdistance y from the wall, finally merging smoothly with the outer(inviscid) stream velocity U(x). At any point in the boundary layer, thefluid shear stress τ, is proportional to the local velocity gradient,assuming a Newtonian fluid. The value of the shear stress at the wall ismost important, since it relates not only to the drag of the body butoften also to its heat transfer. At the edge of the boundary layer, τapproaches zero asymptotically. There is no exact spot where τ=0,therefore the thickness δ of a boundary layer is usually definedarbitrarily as the point where u=0.99 U.

SUMMARY OF THE INVENTION

This patent focuses on technology breakthroughs in boundary layermixing, i.e., on the effects of structural mechanical fillers withparticle sizes ranging from nano to micron using the static filmprincipal of the boundary layer coupled with the coefficient of frictionupon a particle being forced to rotate or tumble in the boundary layerbecause of fluid velocity differentials thereby promoting kinetic mixingthrough the use of the structural fillers.

As an example, a hard sphere rolling on a soft material travels in amoving depression. The material is compressed in front and rebounds atthe rear and where the material is perfectly elastic, the energy storedin compression is returned to the sphere at its rear. Actual materialsare not perfectly elastic, however, so energy dissipation occurs, theresult being kinetic energy, i.e., rolling. By definition, a fluid is amaterial continuum that is unable to withstand a static shear stress,unlike an elastic solid, which responds to a shear stress with arecoverable deformation, a fluid responds with an irrecoverable flow.The irrecoverable flow may be used as a driving force for kineticmechanical mixing in the boundary layer. By using the principle ofrolling, kinetic friction and the increased fluid sticking at thesurface of the no-slip zone produces adherents while the velocityadjacent to the boundary layer produces an inertial force upon theparticle. The inertial force rotates the particle along the surface ofmechanical process equipment regardless of mixing mechanics used, i.e.,static, dynamic or kinetic.

Structural filler particle geometry is based on the fundamentalprinciple of surface roughness, promoting increased adherence to thezero velocity zone in the boundary layer. The boundary layer is wherethe material has its strongest adhesion force or stickiness present. Byusing a particle that has a rough and/or sharp particle surface, theadhesion to the non-slip zone is increased, which promotes bettersurface adhesion than a smooth particle with little to no surfacecharacteristics. The ideal filler particle size will differ betweenpolymers because viscosity differs as well as mixing mechanics producedby sheer forces and surface polishing in mechanical surfaces, whichcreates a variation in boundary layer thickness. A rough and/or sharpparticle surface allows the particle to function as a rolling kineticmixing blade in the boundary layer. The technology breakthrough embodiedin this patent focuses on a hardened particle with sharpened edgesrolling along the boundary layer producing micro mixing with agitationover the surface area in which the boundary layer exist.

Advantages of this technology include:

-   -   Cost savings through the replacement of expensive polymers with        inexpensive structural material.    -   Cost savings by increasing the ability to incorporate more        organic material into plastic.    -   Cost savings by increasing productivity with high levels of        organic and/or structural materials.    -   Better disbursement of additives and or fillers through        increased mixing on the large mechanical surfaces produced by        the boundary mixing.    -   Better mixing of polymers by grinding and cutting effects of the        particles rolling along the large surface area as the velocity        and compression of the polymers impact the surface during normal        mixing operations.    -   Reduction of coefficient of friction on mechanical surfaces        caused by boundary layer effects with drag which is replaced by        rolling kinetic friction of a hard particle in the boundary        layers.    -   Increased production of plastic manufacturing by reduction of        the coefficient of friction in the boundary layer for extruded,        blown or injection molding processes where the coefficient of        friction directly affects the production output.    -   Surface quality improvement on plastics with or without fillers        due to the polish affects caused by kinetic mixing in the        boundary layer on all mechanical surfaces including dyes, molds        and etc. that the materials flow in and around during the        finishing process.    -   Promotion of boundary layer removal by kinetic mixing thereby        having the property of self-cleaning of the boundary layer.    -   Enhanced heat transfer due to kinetic mixing in the boundary        layer which is considered to be a stagnant film where the heat        transfer is dominantly conduction but the mixing of the stag        film produces forced convection at the heat transfer surface.

Solid particles used for kinetic mixing in boundary layer need to havefollowing characteristics:

-   -   The physical geometry of particles should have a characteristic        that allows the particle the ability to roll or tumble along the        boundary layer surface.    -   The mixing efficiency of particles increases with surface        roughness to interact with zero velocity zone or non-slip        polymer surface to promote kinetic friction rather than static        friction.    -   Particles should be sufficiently hard so that the fluid is        deformed around particle for promoting kinetic mixing through        the tumbling or rolling effect of the particle.    -   Particles should be size proportional to the boundary layer of        materials being used so that the particles roll or tumble using        kinetic rolling friction so that the particles are not drug        within the boundary layer, which increases the negative effects        of the boundary layer based on increased surface roughness        restricting flow or can produce the removal of the particle out        of the boundary layer into the bulk fluid.    -   Particles should be able to reconnect in the boundary layer from        the bulk fluid during the mixing process based on particle size        and surface roughness.    -   Particles can be solid or porous materials, manmade or naturally        occurring minerals and or rocks.

Physical Geometry of Particles:

Spherical particles are not ideal because of the following two phenomenathat take place simultaneously. The first phenomenon relates to thesurface friction of the particle in the non-slip zone and the secondrelates to the driving force applied to the particle by fluid velocity,which affects the ability of the particle to induce mixing through atumbling of an irregular shape where a spherical shape tends to justroll along the boundary line. The driving force is produced by fluidflow on the upper half of the boundary layer. Particle shapes can bespherical, triangular, diamond, square or etc., but semi-flat or flatobjects are less desirable because they do not tumble well. Semi-flat orflat objects tumble less well because the cross-sectional surface areahas little resistance to fluid friction applied to its thickness.However, since agitation in the form of mixing is desired, awkward formsof tumbling are beneficial since the awkward tumbling creates dynamicrandom generating mixing zones. These random mixing zones are analogousto having big mixing blades operating with little mixing blades. Someturn fast and some turn slow, but the end result is that they are allmixing. In a more viscous material, which has less inelastic properties,the kinetic mixing by the particles will produce a chopping and grindingeffect due to surface roughness and sharp edges of the particles.

Typical extruded, as well as injection molding plastics are PP, PE, PBHDPP, HDPE, HDPB, Nylon, ABS and PVC, which are some of the types ofplastics used in industry, in which the hardness is proportional to thematerial properties of the plastic. By adding hard fillers into theplastic, a tougher more durable plastic may be reformulated that is morescratch and/or mar resistant than the inherent physical properties ofthe plastic. Common fillers are calcium carbonate and talc, each havinga Mohs hardness scale rating of between one in two. However, it isdesirable to use structural fillers having a hardness of at least 2.5.

A variety of environmentally stable materials suitable for use as hardstructural fillers have not been commercially evaluated by the plasticmanufacturing industry. These fillers are structural, they are hard,light weight and environmentally stable. Some of the reasons why thesefillers have not been used commercially is that they are difficult toformulate and handle. Additionally, these materials may not be aseconomically feasible as previously used fillers. The followinglightweight structural fillers are similar in hardness, density andparticle sizes in the micron range but have not been widely accepted foruse in the plastics industry.

Glass or ceramic micro spheres have been commercially available fordecades. The spheres have had some success in plastic manufacturing butthey have been used mainly in the coatings, adhesives and compositemarket.

Perlite is a naturally occurring silicous rock used mainly inconstruction products, an insulator for masonry, lightweight concreteand for food additives.

Sodium potassium aluminum silicate (volcanic glass) is a micron powderused as a plastic flow modifier to improve the output as well as toproduce enhanced mixing properties for additives as a surface tensionmodifier in the linear viscosity zone.

The structural fillers that have been previously mentioned have a Mohsscale hardness of 5.5, which is equal to window glass, sand and a goodquality steel knife blade.

These structural fillers are not held together by weak forces.Therefore, they keep their rigid shape and do not have lubricatingproperties associated with cleaving of weak chemical bonds betweenmolecular layers, such as may be seen with talc. Particles having a Mohsscale hardness of 5.5 are as hard as what normally would damage theplastic surface. Therefore, resistance to scratching and/or marring bythe sheer hardness of the filler incorporated into the plasticformulation is improved. The structural fillers are preferablylightweight, having a density in the ranges of 0.18 g/cm³ and higher,whereas talc and calcium carbonate have densities ranging 2.50-2.80g/cm³. Therefore, hard structural fillers can reduce the density of theplastic formula.

Micro spheres have recently become of interest for use with extrudedplastics because of their improved strength, which allows them towithstand mechanical pressures without being crushed. As the strength ofthe micro spheres increases, the manufacture cost decreases, which makesmicro spheres an ideal structural filler material for plastics.

Other filler materials for consideration include expanded Perlite.Expanded Perlite has not been commercially used by the plastic industryin extrusion processes because of its micro bubbles and tubes that arenatural properties of the material and can not withstand the extrusionpressures without crushing. The crushing effect of the fillers adds tothe inconsistency volume flow, which affects the dimensional stabilityof the extruded product, which may or may not be acceptable depending onthe application. For this reason, Perlite has not reached commercialviability as structural filler in the plastics field. Perlite can befinely milled, which greatly improves the crush strength of the product,thereby allowing the material the ability to withstand mechanicalextrusion pressures process, thereby gaining dimensional stability. Onereason this material has not been adopted as a filler is that thematerial in its original form has the ability to crush under pressure.

Finely milled Perlite has the same physical properties, just a finermesh, which will withstand higher pressures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of an extruder.

FIG. 2A is a graphical explanation of boundary layer concepts.

FIG. 2B is a graphical explanation of a low speed or laminar boundarylayer.

FIG. 3 is a graph showing the effect of Sodium potassium aluminumsilicate (Rheolite 800 powder) additive on throughput of thermoplasticthrough an extruder.

FIG. 4 is a graph showing the effect of increasing loading using Perliteadditive on throughput of thermoplastic through an extruder.

FIG. 5 is a graph showing the effect of increasing loading of woodparticles while maintaining a 2 wt % Perlite additive loading onthroughput of thermoplastic through an extruder.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

During a jet mill process, particles strike each other to form a sharpedge via a conchoidal fracture. Even though some particle sizeselections will produce different effects with differing polymerselections, it is this edge effect that produces their performance. Theedge effect on hard structural particles facilitates the incorporationof fillers, structural fillers, pigments, fibers and a variety of othermaterials into thermoplastics and polymer material.

Materials that will produce sharp edge effects upon jet milling include:pumice, Perlite, volcanic glass, sand, flint, slate and granite in avariety of other mineable materials. There are a variety of man-madematerials, such as steel, aluminum, brass, ceramics and recycled and/ornew window glass, that can be processed either by jet milling or otherrelated milling processes to produce a sharp edge with small particlesizes. In addition to the listed examples, other materials may also besuitable, provided the materials have sufficient hardness, estimated tobe 2.5 on the Mohs hardness scale.

It is clear to see by the Mohs hardness scale that there is a variety ofmaterials that are harder than 2.5 that would work as likely candidatesto produce sharpened edge effects, thereby working as kinetic mixingparticles relating to the boundary layer as well as a structural fillerto be incorporated in today's modern plastics, polymers, paints andadhesives. The Mohs scale is presented below.

Hardness Mineral Absolute Hardness 1 Talc (Mg₃Si₄O₁₀(OH)₂) 1 2 Gypsum(CaSO₄•₂H₂0) 2 3 Calcite (CaCO₃) 9 4 Fluorite (CaF₂) 21 5 Apatite(Cas(PO₄)₃(OH—, C1—, F—) 48 6 Orthoclase Feldspar (KA1Si308) 72 7 Quartz(SiO₂) 100 8 Topaz (Al₂SiO₄(OH—Y—)₂) 200 9 Corundum (Al₂O₃) 400 10Diamond (C) 1500

The Mohs scale is a purely ordinal scale. For example, corundum (9) istwice as hard as topaz (8), but diamond (10) is almost four times ashard as corundum. The table below shows comparison with absolutehardness measured by a sclerometer.

On the Mohs scale, a pencil lead has a hardness of 1; a fingernail hashardness 2.5; a copper penny, about 3.5; a knife blade, 5.5; windowglass, 5.5; steel file, 6.5.[1] Using these ordinary materials of knownhardness can be a simple way to approximate the position of a mineral onthe scale.

Hardness Substance or Mineral 1 Talc 2 Gypsum 2.5 to 3  Pure gold,silver, aluminum 3 Calcite, copper penny 4 Fluorite  4 to 4.5 Platinum 4to 5 Iron 5 Apatite 6 Orthoclase 6 Titanium   6.5 Iron pyrite 6 to 7Glass, vitreous pure silica 7 Quartz  7 to 7.5 Garnet 7 to 8 Hardenedsteel 8 Topaz 9 Corundum  9 to 9.5 Carborundum 10  Diamond >10 Ultrahard fullerite >10  Aggregated diamond nanorods

Mineral processing technologies have been around for centuries and arehighly specialized. They have the ability to separate particles bymultiple methods as well as shape them into smaller particles. In thecase of these highly specialized solids or porous materials to producethe desired three-dimensional blade like characteristics with sharpenededges in an aspect ratio greater than 0.7 the material must be an impactjet milled or jet milled process. Impact jet milling is a process wherethe process material at high velocity hits a hardened surface to producea shattering effect of particles. In jet milling, opposing jets causethe process material to impact upon itself to produce a shatteringeffect, i.e., conchoidal fractures on the material. The efficiency ofthe kinetic mixing particle due to the resulting with surface sharpness,i.e., bladelike edges (see Appendix 1).

A ball mill process tumbles the material in a batch process removing andesired surface characteristic, e.g., sharpness. For use as particles inthermoplastic extrusions, solid minerals or rocks should be refined toparticles of 10 to 20 mesh or smaller. This is the typical startingpoint for feeding material into the impact jet milled or jet milledprocess. This can be accomplished by a variety of methods that arecommonly available and known by the industry to produce desired particlesizes. The preferred mineral or rock should be able to produceconchoidal fracture. This ensures knifelike edge effects withthree-dimensional shapes. Refer to Appendix 1 for images of conchoidalfractures. In the case of porous minerals or rocks, the characteristicsof the pores being smashed and shattering upon impact during the impactjet or jet milling process creates the three-dimensional knifelike edgeshaped particles. Even though rough and uneven surfaces may besufficient in some mixing applications, in this case, the sharper theparticle the better the results. Refer to Appendix 1 for referenceparticle sizes after jet milling. Man-made materials such as glass,ceramics and metals as well as a variety of other types of materialsmeeting the minimum hardness of 2.5 by the Mohs scale that produce sharpedges with a three-dimensional shape and an aspect ratio larger than 0.7can be used. The impact jet or jet milling process typically with thesematerials produce particles with a mean average of 5-60 μm with a singlepass. Man-made materials like glass may be processed into the desiredthree-dimensional sharp edged particles with an aspect ratio of 0.7 andhigher by means of a mechanical roller mill smashing the particlesrather than jet milling. This is clearly illustrated in the pictures ofAppendices of the raw feed small glass particles before jet milling.

Particle Surface Characteristics:

The mixing efficiency of a particle is increased when surface dynamiccharacteristics of the particle are increased. Examples of particlesurface dynamic characteristics include characteristics such ascolloidal fracture that produce sharp bladelike edges, smooth surfaces,roughness or surface morphology, three-dimensional needlelike shape andthin curved surfaces. Increasing surface dynamic characteristics has atwofold effect. The first effect is that surface characteristics andparticle geometry of a particle having increased surface dynamiccharacteristics enhance surface adhesion to the nonslip zone or thesticky or gluey region, which produces resistance to rolling or tumblingof the particle. The second effect of increasing surface dynamiccharacteristics is an increased resistance of the ability of theparticle to roll and tumble, which results in stronger mechanicalinteraction with the impacting fluid. In the example of a smoothspherical ball rolling across a surface, interaction adhesion with anonslip zone is minimal and the effects on the polymer do not producemuch dynamic mixing. If the material dynamic surface characteristics areincreased, the dynamic mixing is increased thereby increasing cohesionforces in the sticky/gluey region, then increased rotational resistanceis promoted, which increases the cutting or chopping effects of thesharp bladelike particles' ability to grind and cut during tumbling orrotation, which produces kinetic boundary layer mixing.

Examples of desired characteristics for a particle to interact in theboundary layer to promote kinetic mixing are shown in electronmicroscope images found in the below referenced appendices.

Images showing particles exhibiting fracture:

Appendix 1. Ash image is: 7, 8 and 9; and

Appendix 3. Expanded Perlite Images: 3, 4 and 5, Recycled Glass Images:6 through 12.

Even though a variety of materials have the ability to fracture duringmilling processes, the images of Appendix 1 and Appendix 3, mentionedimmediately above, show the characteristics of colloidal fractures thatproduce sharp edges.

Images showing particles having sharp bladelike edges:

Appendix 1. Ash images: 7, 8 and 9; and

Appendix 3. Expanded Perlite Images: 3, 4 and 5; Recycled Glass Images:6 through 12.

A variety of materials have the ability to fracture. For example,striated or vitreous minerals propagate fracture on striation lines,which limits their ability to produce sharp bladelike characteristics.As an example, minerals such as flint and obsidian do not fracture alongstriation lines. As a result, historically these minerals have beenuseful for making objects with sharp edges, e.g., arrowheads,spearheads, knives and even axes. The images of Appendix 1 and Appendix3, referenced immediately above, show this characteristic of sharp knifeblade-like surface characteristics.

Images showing particles having smooth edges:

Appendix 1. Ash images: 7, 8 and 9; and

Appendix 3. Expanded Perlite Images: 3, 4 and 5; Recycled Glass Images:6 through 12.

Smooth edges on a knife blade lowers the resistance needed to cut aswell as lowering resistance to the force needed to be applied to theholding device. This is the same principle that is imparted in sharpsmooth edges of particles, which allow kinetic mixing to take placewhile remaining in the boundary layer tumbling or rolling along thesticky or gluey region. If the surface of a particle is sharp and rough,the resistance due to the surface roughness would be enough to removethe particle from the boundary layer by overcoming the cohesive forcesproduced by the sticky or gluey region. This is why particles having theability to produce sharp smooth bladelike characteristics can remain inthe boundary layer to promote kinetic mixing, as shown in the images ofAppendix 1 and Appendix 3, discussed immediately above, that show thischaracteristic used for kinetic mixing in the boundary layer.

Images showing particles having complex surface geometry:

Appendix 1. Ash images: 7, 8 and 9; and

Appendix 3. Expanded Perlite Images: 3, 4 and 5; Recycled Glass Images:6 through 12.

The complex shapes that are illustrated by the images of Appendix 1 andAppendix 3, referenced immediately above, show bladelike characteristicswith dynamic curves to promote surface adhesion in the sticky or glueyregion.

The complex three-dimensional surface area of the particle is sufficientto promote tumbling or rolling. The above referenced images that showthe ash and the expanded Perlite clearly shows complex surface geometrycharacteristics used for kinetic mixing in the boundary layer.

Images showing particles having needle-like points and curves:

Appendix 1. Ash images: 7, 8 and 9; and

Appendix 3. Expanded Perlite Images: 3, 4 and 5; Recycled Glass Images:6 through 12.

The three-dimensional smooth needle-like tips interact by protrudinginto the moving fluid region adjacent to the boundary layer to promotetumbling or rolling. The smooth needle-like characteristics createenough fluid force to produce rotation while minimizing the cohesiveforces applied by the deformation of the fluid flowing around theparticle, thereby overcoming aerodynamic lift forces, which are notsufficient to remove the particle from the sticky or gluey region. Theimages of Appendix 1 and Appendix 3, referenced immediately above,clearly show the embodiment of three-dimensional needlelikecharacteristics used for kinetic mixing in the boundary layer.

Images showing particles with surface curves:

Appendix 1. Ash images: 7, 8 and 9; and

Appendix 3. Expanded Perlite Images: 3, 4.

The Ash images show a thin smooth curved particle similar to an eggshell. The surface area allows good adhesion to the sticky layer whilepromoting of dynamic lift on this curved thin particle, which promotesrotation thereby producing kinetic mixing in the boundary layer. Theexpanded Perlite clearly shows thin curves on a dynamic surfaceproducing kinetic mixing in the boundary layer. The images of Appendix 1and Appendix 3, referenced immediately above, clearly show theembodiment of thin curved surface characteristics on particles used forkinetic mixing in the boundary layer.

Reactive particle shaping of porous materials:

Appendix 2 Ash unprocessed spheres images: 4-6;

Appendix 1 Ash processed images 7, 8 and 9;

Appendix 4 Course processed expanded Perlite images: 1, 2; and

Appendix 3 Finely processed expanded Perlite images: 3, 4.

These previously mentioned materials because of their unique surfacecharacteristics, Mohs scale hardness of 5.5, thin curved walls, smoothbladelike shape, with three-dimensional surface geometry have theability under high pressure to change their physical particle size whilemaintaining dynamic surface characteristics previously mentioned forkinetic boundary layer mixing. For example particles to large can beswept off the boundary layer into the main fluid where they can undergofracturing produced by high pressure and fluid turbulence reducing theirparticle size. The appropriate particle sizes after fracturing willmigrate towards the boundary layer because of fluid dynamics where theywill come in contact with the sticky or gluey region to promote kineticboundary layer mixing. In conjunction with this example particles sizingmay also take place in the boundary layer against mechanical surfacescaused by fluid impacting pressures. The thin smooth walls whileundergoing fracturing produce sharp knifelike blade characteristicsregardless of fracture point and the hardness of the material helpsmaintain three-dimensional surface characteristics to promote tumblingor rolling in the boundary layer.

Particle Hardness and Toughness:

Mixing blades and high shear mixing equipment are usually made ofhardened steel. Polymers are softer when mechanical agitation is appliedduring mixing. Since particles added to the polymer are passing throughthe equipment, the particles need the ability to retain their shape inorder to function properly. The chemical interactions between moleculeshave been tested and organized based on their hardness. A minimalhardness of 2.5 starting with copper on the Mohs scale or harder will besufficient for a single pass particle to be tough enough for this mixingprocess.

Filler particles should be sized proportional to the boundary layerregion. The size is usually defined arbitrarily as the point whereu=0.99U. Therefore, a particle theoretical starting diameter is theheight measured perpendicular to the surface where u=0.99U. There aremany factors that add difficulties in calculating the parametersassociated with kinetic mixing in the boundary zone, for example:

-   -   1. Filler loading, which produces modified boundary layer        interaction.    -   2. Heat transfer through the walls creating viscosity        differentials.    -   3. Shear effects and continually increased compression induced        by screw agitation.    -   4. Chemical reactions where materials are changing physical        properties such as viscosities, density and etc.

The dynamics of mixing is one of the most complex mechanical chemicalinteractions in the process industry. Particle size will vary fromproduct to product and optimization may or may not be needed.

The chemical industry has produced test methods and tables forhomogeneous liquid and the boundary layer relative thicknesses forcalculating fluid flow properties useful for mechanical equipmentselection and heat transfer properties. The profile assumption may beused as a starting point for the particle size so that the particle willfunction in the boundary layer to increase mixing.

One approach to selecting a suitable particle size is to determine whena particular particle size creates an adverse boundary layer effect byincreasing the drag coefficient. In most processes, this may beidentified by monitoring an increase in amp motor draws during themixing cycle. If the amps increase, then the particle size should bemodified in order to overcome increased power consumption.

Another approach is to see if agitation speed can be increased withoutmotor amp draw increasing, which illustrates friction reduction bykinetic mixing in the boundary layer. For example, FIG. 4 shows thethroughput of a thermoplastic through an extruder at a given screw rpm.It can be seen that the additive of Perlite at 8 wt % increases the RPMsfrom 19 to 45 of screw over the base material of the extruder. Due toequipment limitations, the upper rpm as well as the increased throughputlimit was not able to be ascertained.

FIG. 3 shows that the additive of sodium potassium aluminum silicatepowder (Rheolite 800 powder) to the base material allows the extruder tobe run at higher rpm, reaching a maximum at 29, producing increasedthroughput with the additive working in the linear viscosity zone.

FIG. 5 shows that even when wood content is incrementally increase to 74wt % with 2 wt % Perlite and 24 wt % plastic mixture, in order to findmaximum RPM limitation induced by loading effects could not be reacheduntil 74 wt % wood loading was used, which illustrates superiorthroughput rates as compared to a 49 wt % wood content without Perlite.This clearly shows the improvement of kinetic mixing in boundary layerwhere the viscosity is nonlinear.

Particle Re-Combining to the Boundary Layer:

Particles can be selected to re-interact with the boundary layer if theyare swept off into the bulk fluid during mixing. All fluid materialsflowing through mechanical agitation take the path of least resistance.The velocity profile is affected in agitation by resistive particles tomove in a viscous medium. Therefore, particles that produce resistanceto fluid flow are usually directed towards the boundary layer so thatthe fluid can flow more freely. If the particle size is large, it canbecome bound in fluid suspension because the cohesive forces in theboundary layer are not sufficient enough to resist fluid velocity forcebeing applied to the boundary layer surface, thereby sweeping theparticle back into the fluid suspension. Particles with small sizes willrecombine naturally in the boundary layer based on cohesion forcescaused by surface roughness to promote kinetic mixing even if theparticles become temporarily suspended in the bulk fluid flow.

To verify whether the material is actually enhancing mixing, we mixed alight weight compressible material with poor flow properties withhigh-density polypropylene. The reason this is significant is wood fiberand polypropylene have no chemical attraction and they mixed well withat higher percentage fill levels while increasing throughput of thecombined materials illustrated in FIG. 5.

A limiting factor associated with extruding wood plastic composites is“edge effects,” which is where the material shows a Christmas tree likeeffect on the edges. In some cases, this Christmas tree effect isbecause of improper mixing and resistance of the material which isdragging on the dye exiting the extruder caused by boundary layereffects producing rough edges. It is common in industry to addlubricants in the formulation to overcome this problem. Lubricants allowthe material to flow easier over the boundary layer, thereby allowingthe throughput to increase by increasing the rpm of the extrusion screwsuntil the edge effects appear, which indicates a maximum throughput ofthe process material. Test procedures used that same visual appearanceas an indicator of the fastest throughput which was controlled by theextruders screw rpm.

Experiment #1

-   -   Base formula measured by mass percent    -   3 wt % lubricant: a zinc stearate and an ethylene bissteramide        wax    -   7 wt % Talc: a Nicron 403 from Rio Tinto    -   41 wt % Thermooplastic: HDPE with a MFI of 0.5 and a density of        0.953    -   49 wt %: wood filler: a commercially classified 60-mesh eastern        white pine purchased from American Wood fibers

The materials were dry blended with a 4′ diameter by 1.5′ deep drumblender for 5 minutes prior to feeding.

The extruder was a 35 mm conical counter-rotating twin-screw with a 23L/D.

The process temperature was 320° F., which was constant throughout allruns.

Two other materials were used and added to the base formula to proveconcept these inert hard fillers were:

1. Sodium potassium aluminum silicate (volcanic glass), which is amicron powder used as a plastic flow modifier to improve the output aswell as to produce enhanced mixing properties for additives. 800 meshsolid material hardness 5.5 Mohs scale hardness (Rheolite 800 powder);and

2. Expanded Perlite is a naturally occurring silicous rock used mainlyin construction products, an insulator for masonry, light weightconcrete and for food additives. 500 mesh porous material hardness 5.5Mohs scale.

Experiment #2

Effects of Sodium potassium aluminum silicate (Rheolite 800 powder) onthroughput.

-   -   Baseline material maximum throughput before edge effects        appeared rpm 19=13.13 in.    -   Maximum throughput before edge effects using sodium potassium        aluminum powder    -   0.5 wt %, 22 rpm=15.75 in. an overall increase of throughput        19.9% or approximately 20%    -   1 wt %, 23 rpm=15.75 in. and an overall increase of throughput        20.2%    -   1 wt %, 27 rpm=18.375 in. and an overall increase of throughput        39.9%    -   1 wt %, 29 rpm=19.50 in. and an overall increase of throughput        49.6%        The graphical results of Experiment #2 may be found in FIG. 3

Experiment #3

-   -   Effects of Perlite on throughput    -   Perlite: 8 wt %, rpm 45=21.13 in. an overall increase of        throughput 60.9%    -   Perlite: 16 wt %, rpm 45=19.00 in. an overall increase of        throughput 44.8%    -   Perlite: 25 wt %, rpm 45=15.25 in. an overall increase of        throughput 16.2%    -   Perlite: 33 wt %, rpm 45=13.375 in. an overall increase of        throughput 19.0%        The graphical results of Experiment #3 may be found in FIG. 4.

The reason the high percentages of Perlite were chosen was to remove thepossibility that this material was just a filler. The edge effects ofthe three-dimensional knife blades particles interacting with theboundary layer even at 33 wt % still showed an improvement of 19%greater than the base material. Throughputs of the material could havebeen higher but the rpms limitation on the extruder was 45 and thematerial was being hand fed that is why we believe at 25% the throughputdecreased because of difficulties in feeding such a lightweight materialfor the first time but by the time we got to 33 wt % we had figured itout.

Experiment #4

-   -   Effects of wood on throughput    -   Baseline material maximum throughput before edge effects        appeared rpm 25=17.68 in.    -   Concentration of Perlite was held constant at the starting point        of 2 wt %    -   Wood: 52 wt %, rpm 45=27.6 in. an overall increase of throughput        56.1%    -   Wood: 59 wt %, rpm 45=26.25 in. an overall increase of        throughput 48.5%    -   Wood: 64 wt %, rpm 45=24.17 in. an overall increase of        throughput 36.7%    -   Wood: 69 wt %, rpm 45=24.33 in. an overall increase of        throughput 37.6%    -   Wood: 74 wt %, rpm 30=22.25 in. overall increase of throughput        25.8%    -   The graphical results of Experiment #4 may be found in FIG. 5

The reason this test was chosen was because the loading of a lightweightnatural organic filler into an organic petroleum based materialincreased, the edge effects of poor mixing. There was no maximumthroughput reached on 52 wt %, 59 wt %, 64 wt % and 69 wt % because therpm were at a maximum until 74 wt % at which time the rpm had to bedecreased to 30 rpms to prevent edge effects. The compressible fibers inthe extrusion process act like broom sweeps along the boundary layer.The wood fiber is a compressible filler whose density goes from 0.4g/cm³ to 1.2 g/cm³ after extrusion against the wall which have theability to encapsulate these hard particles in the boundary layer andremove them permanently. It is the effect of the three-dimensionalparticle shape that holds them in the boundary layer with blades thatallow this material to cut softer material and not imbed in the woodfiber, preventing them from being swept away even when the wood fiber isundergoing compression in extrusion process.

There was verification that this material operates in the boundary layerand is self-cleaning. The first day of trial runs we ran the materialsin the order shown by the graphs. The second day of the trial run beforethe wood filler experiment under the same conditions, materials andweather the baseline material had a significant increase of throughput.

Day one, baseline material maximum throughput before edge effectsappeared:

rpm 19=13.13 in.

Day two, baseline material maximum throughput before edge effectsappeared:

rpm 25=17.68 in. with an overall increase of 34.6%.

This was caused by the equipment being polished inside with the highconcentrations of Perlite from day one proving itself cleaning theboundary layer. It implies that the material's three-dimensional sizeand shape with sharpened blade like edges provide excellent kineticrolling capabilities even if the boundary layers thickness changesslightly due to surface cleaning/polishing because of the surface andcontinuous compression forces in the dynamic mixing of the extrusionprocess.

The boundary layer kinetic mixing particles can be introduced throughoutindustry in a variety of ways. For example, in the plastics market:

-   -   The particles can be incorporated into pelletized form from the        plastics manufacturer and marketed as a production increasing        plastic.    -   The particles can be incorporated into colored pellets by        pigment suppliers and marketed as rapid dispersing palletized        pigment.    -   The particles can be incorporated as palletized with filler        inorganic or organic and marketed as self wetting filler.    -   The particles can be incorporated into dry powders and marketed        as self wetting powders such as fire retardants, fungicides and        fillers etc.    -   The particles can be incorporated into liquids as a disbursement        for liquid pigments, plasticizers, UV stabilizer, blowing agents        and lubricants etc.

The boundary layer kinetic mixing particles can be utilized by the paintindustry:

-   -   The particles can be incorporated into paint to increase        dispersion properties of pigments, plasticizers, fungicides, UV        stabilizers, fire retardants, etc.    -   The particles can be incorporated into pigments at custom mixing        stations found in paint stores to help dispense less material        and produce the same color through better mixing and dispersion        property mixing.    -   The particles can be incorporated into dry powders from        additives manufacturers to help disperse fire retardants,        fillers etc.    -   The particles can be incorporated into spray cans to increase        the mixing along the walls promoting boundary layer mixing.    -   The particles can be incorporated into two component mixing        materials to promote better surface area mixing or boundary        layer and liquid to liquid interface boundary layer mixing        urethanes, urea and epoxies etc.    -   The particles can be incorporated into a lubricant package used        for cleaning spray equipment through continuous recirculation        with chemical cleaners.

The boundary layer kinetic mixing particles can be utilized by thelubrication industry.

The particles can be incorporated into oils to promote better flowaround surfaces by lowering the boundary layer friction zone producingbetter wetting with no break down of temperature on this additivebecause it's a solid particle: cars, boats, planes, bicycles internaloil external oil, etc.

The particles can be incorporated into oils for whole household cleaningallowing the oil to spread more evenly as a thinner layer less likely tobecome sticky over time because the layer is thinner.

The particles can be incorporated into break fluids, hydraulic fluids ofall types producing a better response to fluid motion because theboundary layer moves with kinetic mobility when pressure is applied.

The particles can be incorporated into fuel additives promotes betterdisbursement in the fuel as well as a self-cleaning action due toparticles interacting on boundary layers throughout the whole entireflow path of combustion including the exhaust where the particles stillhave a cleaning effect.

The particles can be added as a lubricant and disbursements directlyfrom the refinery. The particles will not only help a car's lubricatingeffects and cleaning the system but the particles will also increase thelifespan of the gasoline pumps due to residue build up of sludge typematerial in the boundary layers.

The boundary layer kinetic mixing particles can be utilized to increaseflow properties. Most liquid material flowing through a pipe, pumpsystem and/or process equipment undergo boundary layer effects based ondrag coefficient regardless of the surface geometry which thistechnology can reduce drag by promoting kinetic boundary layer mixing,with a self-cleaning effect. This will allow pipes and process equipmentto perform at optimum levels.

The boundary layer kinetic mixing particles can be utilized to increaseheat transfer. Because the boundary layer is being kinetically moved itis no longer a stagnant fluid heat transfer zone this increases the heattransfer properties on both sides. Now the stagnant boundary layer hasturned into forced convection on both sides not just one, the fluid tofluid and the fluid to surface.

The boundary layer kinetic mixing particles can be utilized by the food,pharmaceuticals and agriculture industry. Because the selection of theparticles can be approved by food and drug the processing of foodthrough plants into its packaging can be enhanced and process equipmentcan mix things more thoroughly.

Thus, the present invention is well adapted to carry out the objectivesand attain the ends and advantages mentioned above as well as thoseinherent therein. While presently preferred embodiments have beendescribed for purposes of this disclosure, numerous changes andmodifications will be apparent to those of ordinary skill in the art.Such changes and modifications are encompassed within the spirit of thisinvention as defined by the claims.

1-62. (canceled)
 63. An improved additive for use in a fluid flowingthrough equipment where the flowing fluid has a stream velocity (U) anda boundary layer flow velocity (u), wherein (U) and (u) are affected byfiller loading, heat transfer, shear effects and chemical reactions,wherein the improvement comprises: particles having a sharp conchoidalsurface and a complex three-dimensional surface area, said particleshaving a diameter approximately equal to a theoretical startingdiameter; wherein said particle theoretical starting diameter is definedby a height measured perpendicular to a surface where u=0.99U.
 64. Theimproved additive according to claim 63 wherein said complexthree-dimensional surface area comprises a smooth, sharp surface. 65.The improved additive according to claim 63 wherein said complexthree-dimensional surface area comprises a smooth, sharp, blade-likesurface.
 66. The improved additive according to claim 63 wherein saidcomplex three-dimensional surface area comprises a smooth, curvedsurface.
 67. The improved additive according to claim 63 wherein saidparticles comprise a jet milled material.
 68. The improved additiveaccording to claim 63 wherein said particles comprise an impact jetmilled material.
 69. The improved additive according to claim 63 whereinsaid particles comprise a ball milled material.
 70. The improvedadditive according to claim 63 wherein said particles comprise a rollermilled material.
 71. The improved additive according to claim 63 whereinsaid particles have a Mohs hardness value of greater than 2.5
 72. Theimproved additive according to claim 63 wherein said particles have ahardness sufficient to deform said fluid as it flows around saidparticles, thereby promoting kinetic mixing through the tumbling orrolling effect of the particles.
 73. The improved additive according toclaim 63 wherein said particles are of a size that remain primarily in aboundary layer of said flowing fluid, said particles having anappropriate size with respect to the boundary layer such that fluidflowing over said boundary layer cause rolls or tumbles of saidparticles, for creating kinetic rolling thereby producing mixing in saidboundary layer.
 74. The improved additive of claim 63 wherein saidparticles promote boundary layer renewal of said flowing fluid bykinetic mixing.
 75. The improved additive according to claim 63 whereinsaid particles are selected from a group consisting of porous materials,manmade materials, and naturally occurring minerals.
 76. (canceled) 77.The improved additive according to claim 63 wherein said equipment is apump or process equipment having connections that are open ended singlepass or are continuous for recycle operations.
 78. The improved additiveaccording to claim 63 wherein said particle diameter results in particleinteraction in a boundary layer of said flowing fluid to achieve one ofan increase in additive dispersion in said fluid, or to increase surfacequality of said fluid exiting said equipment.
 79. The improved additiveaccording to claim 63 wherein said particles are incorporated into saidfluid by providing pellets which have said particles contained therein,and forming the fluid from said pellets, said fluid of which has theparticles dispersed therein.
 80. The improved additive according toclaim 63 wherein said particles are incorporated into oil.
 81. Theimproved additive according to claim 63 wherein said particles areincorporated into a paint.
 82. The improved additive according to claim63 wherein said particles are incorporated into a fire retardant. 83.The improved additive according to claim 63 wherein said particles areincorporated into a heat transfer fluid.
 84. The improved additiveaccording to claim 63 wherein said particles are incorporated into apigment.
 85. The improved additive according to claim 63 wherein saidparticles have an aspect ratio greater than 0.7.
 86. The improvedadditive according to claim 63 wherein said fluid is a plastic.
 87. Theimproved additive according to claim 63 wherein said fluid is a polymer.